linear function

15 LETTERS · STARTS WITH L

linear function is a valid 15-letter word worth 19 points in Scrabble and 25 points in Words with Friends.

SCRABBLE WORDS WITH FRIENDS

L1I1N1E1A1R1F4U1N1C3T1I1O1N1

1 + 1 + 1 + 1 + 1 + 1 + 0 + 4 + 1 + 1 + 3 + 1 + 1 + 1 + 1 =19 PTS

DOUBLE WORD → 38TRIPLE WORD → 57

MEANING

What does linear function mean?